The emperor moth Saturnia pavonia in the southern part of the Netherlands: distribution,phenology and food (Lepidoptera: Saturniidae)Saturnia pavonia is a large and beautiful moth. It was thought that the species was becomingrare in the Netherlands. In the period 1986-2006 the species was surveyed in the province ofNoord-Brabant and the northern and middle part of the province of Limburg. It was shownthat the emperor moth was present in 40% of the 250 investigated 5 km squares, especially onheath land and in forests. It became clear that the species, however conspicuous in appearance,has a largely hidden lifestyle. Although the males can be seen flying over heath land, most arehidden in the vegetation. Furthermore the males fly only in the late afternoon and evening.Females are even less active and both sexes are scarcely attracted to light traps. The caterpillarsare sometimes found high in trees and shrubs, but this research shows that most are hiddendeep in the vegetation. The flight period started ten days earlier than in 1960, mentioned inthe Dutch literature.In Central Europe Filipendula ulmaria is an important food plant. In the Netherlands mostcaterpillars were found on Calluna and Erica, seldom on other plans, and only occasionallyon Filipendula.